[Study of some pharmacological properties of a new adenine derivative].

It is established that the new compound, 9-[2-(4-isopropylphenoxy)ethyl]adenine (9-IPE-adenine) in a dose of 10 mg/kg per day produces neuroprotective effect in rats with brain ischemia model. 9-IPE-adenine decreased the neurologic deficiency 1.2 times more effectively (p < 0.

[Investigation into the vestibular protective properties of melatoninergic agents].

Experiments with rats showed that melatonin (2.5 mg/kg) produces a distinct vestibular protective effect excelling promethazine (50 mg/kg) as a reference agent, and also antidepressant agomelatine (5 mg/kg) as another melatoninergic agent. Lusindol, a blocker of MT1/MT2-receptors (2.

[On the mechanism of ikaron-1 anti-naupathia action].

Pneumomicroinjection of vestibuloprotector ikaron-1 (Russia) in specific neurons of the medial vestibular nucleus (MVN) was studied in cats immobilized by muscle relaxants using microelectrode devices. The original preparation had a direct effect on the majority of MVN neurons (95 %). Thirty four neurons of 37 cells (92 %) developed an inhibitory response, only one cell (3 %) was activated and 2 neurons (5 %) were areactive.

[Analgesic effect of succinate-containing preparations].

It was established that mexidol (100 mg/kg, i.v.) in contrast to cytoflavin (1 ml/kg, i.

[Radiation lesion formation and character of repair processes in the hematopoietic system of primates exposed to continuous and fractionated gamma-irradiation by equally effective doses].

The article is dedicated to comparison of the biological effectiveness of continuous and fractionated gamma-irradiation of rhesus macaques by equally effective doses. These radiation conditions are broadly used in radiobiological experiments. Specifically, they are applied in modeling radiation effects on cosmonauts during extended exploration mission.

[Investigation of anti-hypoxic action of 3-hydroxypyridine derivatives in animals with some types of experimental pathology].

Experiments with occlusion of the common carotid artery in mice demonstrated that, unlike mexidol and SK-170, single injection of new derivatives of 3-hydroxypyridine (3-HP) SK-100 and IBKhF-2, and semax have an anti-hypoxic action on the model of acute normobaric hypoxia with hypercapnia. In analogous experiments with rats the distinct anti-hypoxic action was produced by 4 new 3-HP derivatives (SK-100, SK-170, IBKhF-22 at the dose of 100 mg/kg and IBKhF-2 at the doses of 10 and 30 mg/kg--extension of life span by 25-39%), mexidol (100 mg/kg) and reference-class antihypoxant amtisol (30 mg/kg, life span expansion by 19 and 27%, respectively). A series of experiments with rats with acute pancreatitis, a distinct anti-hypoxic action was shown by SK-100, SK-170 at 100 mg/kg and IBKhF at 10 and 30 mg/kg (life span extension by 26-40%), mexidol (100 mg/kg) and amtisol (30 mg/kg) which extended life span by 17 and 22%, respectively.

[Effect of intermittent hypergravity on cerebellum Purkinje's cells in suspended rats].

The quantitative cytochemical and morphometrical techniques applied in the experiment with 24-d tail-suspension of rats demonstrated a decrease of cytochrome oxidase activity and downsizing of Purkinje's cell bodies in the proprioceptive cerebellum (cerebellar vermis upper central lobule), as well as a decrease of cytochrome oxidase activity in Purkinje's cells in the vestibular cerebellum (nodulus). The observed suppression of the Purkinje's cells functional activity indicates reductions in the proprioceptive and vestibular afferent inputs to these cells during simulation of the microgravity effects in rats. Intermittent exposure to hypergravity (2 G, one hour a day) prevented the decreases in cytochome oxidase activity in Purkinje's cells of both the proprioceptive and vestibular cerebella of tail-suspended rats suggesting a nearly same level of functioning as in the vivarium controls.

[Reaction of the neuronal population of rat's L5 spinal ganglia to primary and repeated modeling of microgravity effects].

Cytochrome oxidase activity as well as neurons' body and nuclei sizes were measured in the spinal L5 ganglia receiving the hindlimb afferent input during primary and repeated 14-d tail-suspension of rats. The measurements were performed using the quantitative cytochemical and morphometric techniques. The animals were suspended 30 days and returned to vivarium.

[Influences of primary and repeated modeling of microgravity effects on spinal motoneurons l5 in rats: cytological analysis].

The cytochrome oxidase activity, sizes of bodies, nuclei, and nucleoli of alpha-motoneurons from the L5 anterior horns were investigated in rats once or repeatedly suspended by tails to model the effects of microgravity. Rats were suspended 30 days, then held in vivarium 30 days w/o any behavior restriction and suspended once again 14 days simultaneously with rats that had not been suspended before. The first-time 14-d suspension reduced the cytochrome oxidase activity as well as sizes of bodies and nuclei in alpha-motoneurons which pointed to hypofunctioning of these nervous cells.

[Reproductive function and viability of progeny in female rats under unfavourable influences in run up to puberty].

Wistar female rats were subjected to a 3.5-day water deprivation once a week in the period of 1.5 to 3 months of age.

[Intermittent exposure to hypergravity of rats deprived of support to the hind limbs. analysis of the somatosensory cortex ultrastructure].

Intermittent hypergravity was evaluated as a method to prevent the unfavorable nervous effects of microgravity. It was shown that intermittent exposure to hypergravity (2 G, 1 h. a day) of rats during 24-d tail-suspension put a barrier to changes in the ultrastructure of the brain somatosensory cortex associated with a reduction in the afferent input to the somatosensory cortex from the hind limbs.

[Functioning of the brain vessels in rats after repeated simulation of some effects of microgravity (histological analysis)].

Histological methods were employed to investigate brain vessels of rats subjected to 30-d tail-suspension and 30-d readaptation in the horizontal position afterwards, and suspended again for 14 days simultaneously with other rats that had no such experience in the past. Repeated suspension produced, although there was blood redistribution to the cranial end, much less profound changes in brain vessels as compared with the previous 30-d suspension and the first-time suspended mates. This suggests an unknown arterial mechanism triggered in the region forward of the extracerebral arteries of the brain surface which hampered an excess blood flow to the brain during repeated suspension.

[Blood plasma volume dynamics in monkeys during immersion].

Dynamics of blood plasma volume (PV) was studied with indirect methods (hematocrit count, hemoglobin, total protein and high-molecular protein) during 9-d immersion of monkeys Macaca mulatta. The animals were donned in waterproof suits, motor restrained in space seat liners and immersed down to the xiphisternum. Two monkeys were immersed in the bath at one time.

[The influence of hypokinesia on the mother-fetus system].

In experiments with rats effects of hypokinesia on the course of pregnancy and the mother-fetus system were investigated. Immobilization in penal-type cages of female rats on days 8 through to 19 of pregnancy gave rise to significant shifts in mother's organism, i.e.

[Repeated hypergravity: morphologic investigations of pituitary, thyroid, blood and bone marrow in rats].

To elicit the mechanism of facilitating the mammals' adaptation to repeated changed gravity influence, the pituitary, thyroid, blood and bone marrow were investigated morphologically in rats exposed to single and repeated hypergravity (2 g) and Coriolis accelerations for 5 days during rotation on centrifuge. No distinct difference in blood and bone marrow cytology was determined after single and repeated exposure to 2 g and the Coriolis accelerations. Compared to single and in contrast to single and repeated exposures to the Coriolis accelerations, a repeated 2 g influence produced some structural changes in somatotropic cells of the pituitary and thyroid parenchyma of the thyroid.

[The effect of weightlessness on erythrocyte resistance in vivo and in vitro].

One of the significant changes developing in animals and humans in the space mission environments is a decreased volume of red blood mass. For the analysis of causes of this phenomenon it is reasonable to compare the data on erythrocyte resistance to hemolysis in vivo and in vitro obtained in the rat experiments on Cosmos biosatellites. After 18 to 22-day space missions, the osmotic resistance of erythrocytes in vitro in animal blood samples and the level of spontaneous hemolysis in vivo directly in the vascular bed of rat have been determined.

[General characteristics of an experiment to study the ontogeny of rats on board the Kosmos-1514 biosatellite].

Ten female Wistar rats were exposed to zero-g during 5 days, i. e., from gestation day 13 to day 18.